Answer:
Increase, Decrease
Step-by-step explanation:
A decrease in the price of input reduces its cost of production. Lower cost of production means the product will be sold at a lower price. As per the law of demand, a reduction in the price of a good increases its demand. The reduced beef price will increase its demand.
If pork and beef are substitutes goods, consumers can choose either of them. An increase in the demand for one results in a fall in demand for the other. A reduction in the price of beef will lead to a rise in demand. Customers will prefer beef over pork due to its low price. The demand for pork will reduce as customer's preference will be on beef.